How Do Icebreaker Ships Cut Through Ice?

Icebreakers do not slice through ice — they climb on top of it. The bow is rounded and sloped so the ship rides up onto the ice sheet. The vessel's immense weight (nuclear icebreakers can displace over 25,000 tonnes) then cracks the ice downward. The hull is reinforced with thick high-tensile steel and an "ice belt" at the waterline. Ballast tanks can shift water between bow and stern to rock the ship and break stubborn ice. Propulsion comes from diesel-electric or nuclear-powered systems delivering up to 75,000 horsepower. Russia's Arktika-class nuclear icebreakers can break through ice over 2.8 metres thick and operate continuously for years without refuelling.